I need a way to dynamically switch between using only one LCD and boths with twinview, without killing X (thus retaining open applications and work in KDE) if possible.

Having read and read, I am frankly confused as to the multitude of options I seemingly have.

Could / would some kind soul take pity and tell me if the following assumptions are right:

1. Multiple layouts work only by restarting the X-server in between switches, so not what I want.
2. I should keep twinview enabled, even when only using one monitor.
3. I should - instead of layouts - use metamodes, ex.
DFP-0: 1280x1024_75 +0+0, DFP-1: NULL;DFP-0: 1280x1024_75 +0+0, DFP-1: 1280x1024_75 +1280+0;
3a. If so, I should be able to change between the two with <ctrl>+<alt>+<plus>.
4. When not using the secondary screen, I tend to turn it off. In order for this not to be a problem (with detection), I should ensure by setting the connected option to "DFP,DFP".

If someone would confirm or refute the above, I shall be better able to direct my further searching better (and maybe more to the point, exlude what I do not need concern myself with).

I am fairly new to Linux but I am really doing my best to get to gribs with this and reading before asking - I just need the direction clarified a bit.
Thank you for your patience.